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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Succession in the Understory of Red Pine Plantations in Southern Ontario

Spitale, Salvatore Patrick January 2011 (has links)
Thousands of hectares of red pine (Pinus resinosa Ait.) plantations were established during the early 20th century to restore abandoned agricultural lands and increase forest cover. Concern over the ecological integrity [i.e. the degree to which a community is determined to be characteristic of its natural region, including abiotic and biotic components, likely to persist and maintain the rates of change and supporting processes (Canada National Parks Act (S.C. 2000, c. 32) 2011) of these plantations and a desire to increase native forest cover has prompted a more thorough understanding of the understory succession of these plantations. This study addresses the question, how does the understory vegetation composition and diversity in managed red pine plantations compare to the understory of a reference deciduous forest?. I examined the understory diversity in a chronosequence of managed red pine plantations owned by Simcoe County. Biophysical characteristics including diffuse non-interceptance (DIFN), tree regeneration, litter depth, and soil physical and chemical properties were gathered from three replicates of each of four age groups and from a reference deciduous forest group in order to determine how each variable changed and influenced the succession of the understory diversity. Field investigations were completed during the spring, summer, and fall of 2009 in order to examine seasonal differences in diversity. A two-way analysis of variance with a Tukey’s post hoc test was used to determine if the forest groups were significantly different from each other for each variable measured. Species diversity (measured by the Shannon-Wiener Index) generally increased with plantation age and seasonal differences were apparent. A lack of significant difference between the oldest plantation group (est. 1927-1932) and the reference forest group indicates diversity is increasing; this is intriguing because, in contrast, species composition is only 30% similar. This may indicate either not enough time has passed for the understory to regenerate or the understory in the plantations is succeeding in a different trajectory. Furthermore, spring ephemeral species were lacking in the understory of the plantation forests indicating this phenological group is not regenerating in the plantations. Tree density is generally increasing in the plantation groups and the dominant tree species regenerating in the oldest plantation group includes a similar suite of species to that found in the reference forest groups. This indicates that the canopy is succeeding towards a native forest community. Pearson correlation analysis revealed that litter depth is significantly negatively correlated to diversity in the summer and fall (p<0.01). Litter depth was also the primary predictor variable produced by the forward stepwise regression in the summer and fall indicating that litter depth is a major driver of diversity. From comparative studies, a deeper litter layer often inhibits the germination and emergence of herbaceous species; from my study, this may explain the lack of spring ephemerals in the plantation groups observed. DIFN was significantly negatively correlated to diversity in the spring (p<0.01) and was the predictor variable for spring diversity indicating that light characteristics in the spring are a major variable influencing spring diversity. With increasing age of plantation group the DIFN followed a similar pattern to the reference forest group indicating that the thinning regime and regeneration is shifting the light characteristics to that found in a natural forest stand. I conclude that the thinning regime in red pine plantation is promoting the regeneration of trees and increasing the diversity of understory vegetation. However, in order to direct the successional trajectory of the understory vegetation of red pine plantations to a composition similar to the native woodlands of that area, a modified management program should be considered and active restoration should be implemented.
182

Towards a Strategic Communications Plan: Providing Community-Informed Insight into the Role of the Biosphere Reserve on the Oak Ridges Moraine

Law, James Sik Yin January 2012 (has links)
The implementation of UNESCO Biosphere Reserves (BR) in Canada is strongly dependent on grassroots community-based support and understanding. The recent calls for the Oak Ridges Moraine and adjacent Greenbelt lands (ORMGB) to be designated a BR require that a communications strategy be created to garner local support. Taking into consideration complex systems theory, this study looked to build a communications framework that combined higher-scale social organizing literature like social movement and environmental campaigns more detail-focused group dynamics and strategic communications research. Applying this framework to the ORMBG landscape revealed key target audience groups and messaging for the BR communications strategy.
183

Akimiski Island, Nunavut, Canada: An Island in Dispute

General, Zachariah 20 September 2012 (has links)
On April 1, 1999, Akimiski Island, Northwest Territories, Canada, became part of the newly created Inuit-dominated territory of Nunavut, even though the Inuit never asserted Aboriginal title to this island. This is why the Omushkegowuk Cree of the western James Bay region of Ontario, Canada, assert Aboriginal title over this island. Essentially, the Government of Canada has reversed the onus of responsibility for proving Aboriginal title from the Inuit to the Cree. In this paper, we examined whether the Omushkegowuk Cree fulfill all the criteria of the common law test of Aboriginal title with respect to Akimiski Island, utilizing all available printed and online material. All criteria of the common law test of Aboriginal title were met; however, the written record only alludes to the Cree using Akimiski Island at the time of first contact and prior, Cree oral history was consulted to illuminate upon this matter. I documented and employed Cree oral history to establish that Cree traditional use and occupancy of Akimiski Island was “sufficient to be an established fact at the time of assertion of sovereignty by European nations” (INAC, 1993:5; INAC, 2008); thereby, fulfilling criterion 2 of the test for Aboriginal title. As the Cree have now met all criteria of the common law test for proof of Aboriginal title in Canada, with respect to Akimiski Island, a formal land claim should be considered by the Cree.
184

Crisis Overstated? Knowledge Gaps and the Aging Water Workforce

Yessie, Steven January 2012 (has links)
ABSTRACT Beginning in 1946 fertility in Canada and other Western countries increased to rates unequaled throughout the rest of the 20th century. Sixty five years since the beginning of the baby boom, as this generation was labelled, workers are retiring or nearing retirement on scale not previously witnessed. This workforce exodus has signalled concern among scholarly, professionals and government sources alike. The public sector has been identified as particularly at risk with both and older average worker age and a low average retirement age. Within the public sector, jobs relating to the Canadian water workforce have similarly been identified for retirement concerns, specifically among senior positions. Retirements have highlighted aspects of concern for the future: knowledge leaving the workplace, and recruiting talent for the future. Among primary concerns is for knowledge that has no place in traditional documentation methods, tacit knowledge. Although transferring this knowledge presents difficulties, strategies include retaining knowledgeable employees and creating programs that facilitate knowledge exchange. Mentorship programs are one such strategy identified specifically for tacit knowledge transfer. This thesis considers how retirements would affect the water workforce including positions centred on conservation and policy efforts, as well as the water utilities industry. Although a few studies have focused on water utilities, this area of the public workforce had largely been ignored. Conducting fourteen interviews within three case study municipalities, primary data was gathered to determine how the water workforce would be affected by retirements, if retirements created concerns with respect to inter-organizational networks, and what strategies would be most suited to the needs of participating organizations.
185

Keeping Up With the Joneses: Electricity Consumption, Publicity and Social Network Influence in Milton, Ontario

Deline, Mary Elizabeth January 2010 (has links)
Abstract This study used an exploratory research focus to investigate if making electricity consumption public and subject to social norms and networks resulted in consumption decreases for households in Milton, Ontario. In the first phase, Milton Hydro identified customers who fell within an average annual electricity consumption category and these customers were invited to participate by mail. Due to lack of participant uptake, cold-calling, targeting of service and faith groups and commuters, and snowball sampling were employed to obtain a total participant size of 17. The second phase saw participants grouped according to social network type (occupational, faith group, etc) and exposed to approval or disapproval indicators within their group about their daily electricity consumption rates via an on-line ‘energy pool’. There were five main groups: one of neighbours, one of members of a faith group, one of members of a company, one of strangers and one of a control group. Group members saw other members’ indicators with the exception of the control group, whose indicators were privately delivered. All group’s electricity consumption was tracked through daily smart meter readings. Participants also had the option of commenting on each other’s electricity use via an online ‘comment box’. In the third phase participants were asked to participate in a questionnaire to assess: 1) the perceived efficacy of the intervention; 2) perceptions of electricity consumption; and 3) the influence of the group on these perceptions. This sequential methodology was chosen for its ability to “...explain significant (or non-significant) results, outlier results, or surprising results” (Cresswell, 2006, p. 72). The findings of this exploratory research seem to suggest the following: 1) that publicity or group type does not seem to affect electricity consumption in comparative electricity consumption feedback for this study; 2) that participants used injunctive norms to comment on their electricity consumption but directed these comments solely at themselves; and 3) that the stronger the relationships in the group, the more likely participants were to engage with the website through checking it and commenting on it. This study may be useful to those in the fields of: 1) electricity conservation who wish to leverage feedback technologies; 2) social networks who wish to better understand how tie strength interacts with social norms and; 3) those in social marketing who wish to develop norm-based campaigns.
186

Examining the Social Acceptability of Cisterns in Rainwater Harvesting for Residenital Use in the Region of Waterloo, Ontario

Fortier, Julia, Maureen 30 April 2010 (has links)
As water infrastructure in urban Ontario strains to meet the demands of a growing population, alternatives to the conventional water supply approach that complement demand management strategies are important to enable more sustainable water use at the household level. The adoption of rainwater harvesting (RWH), for indoor and outdoor uses by single-family households can reduce a households withdrawals on municipal water by 30% if rainwater is used for toilet flushing, laundry and outdoor uses (Despins 2009). The amount of potable water savings because of RWH is influenced by the rate of adoption and the allowed uses of rainwater at the individual household scale. The adoption of RWH systems would lead to reductions in potable water demand, which, in turn would lead to reduced demands on municipal water sources (e.g., groundwater or surface water), and storm water infrastructure resulting in overall reduced ecosystem stress and increased resiliency for climate change adaptation. Greater onsite storm water retention would mimic natural processes and would help reduce excess overland runoff that can result in water contamination. Presently, RWH systems tend to be more accepted and utilized in rural areas. However, there is a history of cistern use in rural and non-rural Waterloo. This history and capacity seems to be largely forgotten or unknown by urban citizens and local government officials. Century houses’ cisterns are often removed or filled in due to: a perceived lack of need, safety concerns and disrepair because of disuse. The increasing popularity of “green” building features and certifications have added some RWH systems for indoor and outdoor use to the urban environment, however, these remain limited instances. Moving RWH forward requires commitment from the Provincial and municipal government. Municipalities’ actions must support the sustainability objectives often referenced in their legislation and policy. This study establishes the drivers of RWH and examines the barriers to practice in the urban environment by examining existing examples and academic literature RWH systems within Canada and internationally. Results from a survey conducted in the City of Waterloo are used to reflect the systems user’s perspective. Interviews with municipal officials and RWH experts further highlight the drivers and barriers to RWH in urban Ontario. Based on the surveys, participants were generally willing to consider adopting RWH systems and a greater use of rainwater in the house, although a lack of information acts as significant barrier. However, Waterloo municipal officials who participated in the interviews described a much less enthusiastic attitude towards RWH. Although barriers identified in this research, including: legislative barriers, risk tolerance, perceptions of water abundance and economic realities shape the willingness to adopt RWH, this study indicates the barriers are surmountable through education and economic signaling.
187

Integrating Mitigation and Adaptation to Climate Change in Orissa, India: Coupling Entrepreneurial Agricultural Mechanization with Village-Based Biodiesel Production

Dabby, Nava Samara 07 September 2010 (has links)
India’s strong agrarian economy, global location and climatic zoning make it highly vulnerable to the potential effects of climate change. Recent evidence of shortening cropping seasons has raised interest among academics and policy makers in tools for adaptation. Timely sowing and appropriate mechanization have been identified as attractive adaptation tools. Mechanization using locally produced biodiesel in place of conventional fossil fuel provides a relatively low-cost and sustainable opportunity to mitigate carbon emissions. An enterprise model in which farmers invest in machinery for custom hire coupled with community-produced biodiesel offers one approach to integrated adaptation and mitigation mechanisms for climate change. This research analyses agricultural practices and small farm mechanization in the state of Orissa, India, drawing on a village case study. Primary data is from twelve key informant interviews with farmers, academics and NGO representatives in India. Secondary data analysis includes Indian and Orissan government documents and reports from international organizations regarding agricultural mechanization, sustainability, resiliency and climate change. The results of this study indicate that joint mitigation and adaptation mechanisms implemented at the community level can address impacts of climate change while also offering opportunities for livelihood benefits, poverty alleviation and income generation. This research contributes to growing literature on adaptation and mitigation tools for climate change and adds an integral focus on small-scale opportunities within the broader scope of sustainable agriculture and biofuel development in India.
188

Native bee (Hymenoptera: Apiformes) response to ecological restoration in southern Ontario

McLeod, Kylie January 2013 (has links)
Bee declines have been reported globally and habitat loss and degradation due to urbanization and agricultural intensification are two of the primary drivers. Native bees play a critical role in plant reproduction, and declines in abundance and diversity of bees are expected to impact flowering plant biodiversity and productivity of insect pollinated agricultural crops. Habitat restoration can help mitigate declines by increasing the amount and quality of available bee habitat. However, outside of agroecosystems bees are rarely specified in restoration targets and little is known about how they respond to habitat restoration. My thesis addresses this knowledge gap by: (1) documenting the structure and function of the native bee community at a restored wet meadow to establish a baseline for future monitoring activities, (2) comparing the influence of two restoration approaches on the established bee community, and (3) exploring changes in functional groups and pollination function with time since restoration. I sampled bees at degraded, restored, and (semi)natural habitats at 12 sites in four locations in southern Ontario. I used a combination of structural (abundance, richness, and evenness) and functional (guilds based on social and nesting habits and plant-pollinator interaction networks) characteristics to describe and compare bee communities. I collected a total of 10,446 bees from 30 genera and six families representing a range of phenologies, social behaviours, and nesting habits. At Dunnville Marsh, a restored wet meadow, I collected 5,010 bee specimens from 27 genera and six families. The bee community at Dunnville Marsh was diverse and well connected within 4-6 years of restoration, emphasizing the importance of wet meadows as native bee habitat. However, wood nesters and cleptoparasites were relatively uncommon suggesting that the community may be less stable compared to older habitats. Between 2005 and 2008, individual fields at Dunnville Marsh were dug with pits and mounds before planting and seeding or were seeded into weedy ground. Digging pits and mounds did not convey a clear advantage to the establishing bee community, but genus richness was greater in pit and mound sites (p=0.04). As well, the restoration approach used influenced the relative representation of guilds within the community. Ground nesters and wood nesters were significantly more abundant in pit and mound treated sites (p<0.001), perhaps reflecting the larger amounts of bare ground (p<0.001) and the greater potential for sapling survival on mound tops. Stem nesters were more abundant in planted sites (p<0.001), and floral richness and abundance did not differ between the two restoration approaches. Finally, diversity and evenness of guilds based on social and nesting habits increased with age since restoration, indicating that communities in (semi)natural habitats are more functionally diverse than those in restored habitats, but that communities in restored habitats are more functionally diverse than those in degraded habitats. Relative abundance of guilds changed with age since restoration in ways that reflected structural habitat changes associated with succession. Degraded sites had the highest relative abundance of ground nesters, while (semi)natural sites had the highest relative abundance of wood nesters. Plant-pollinator interaction networks did not demonstrate clear trends with respect to age since restoration, but indicated that communities that establish in response to non-targeted restorations can be diverse, robust to extinction, and well connected.
189

Perception of Naturalness in a Hybrid Landscape: A Case Study of Citizens Engaged in Oak Ridges Moraine Conservation

Ferrier, Elaine Allison January 2011 (has links)
Conservation in Canada is increasingly driven by land use planning processes. Approaches to governing nature conservation have shifted dramatically from protecting isolated pristine areas to greater attention to the remaining fragments of greenspace in urban, semi-urban and rural areas. The ways that societies govern and use nature are always changing, and these physical management actions are connected to deeply rooted cultural norms and values about the ideal relationship between humans and nature. In the land use planning approach to conservation, citizens and governments find value and construct meaning for remaining nature rather than beginning with normative considerations of what is most worthy of protection. At the root of this conservation planning trend is a growing appreciation for hybrid nature that is valued as natural in spite of the past or present influences upon it. This represents a dramatic shift from the traditional values involved in North American nature conservation, where nature was most valued for its perceived separation from human influence and protected to maintain its untouched qualities. In light of these ideological shifts in the ways that Canadians value and in turn manage nature, is there a corresponding change in the ways that conservation activists perceive environmental value and evaluate naturalness? An increasing number of studies demonstrate that public valuation of nature is not limited to pristine environments: even highly disturbed environments can be valued as natural and are not perceived as a form of lesser nature. Conceptions of what is natural and what is not are highly subjective and variable; in particular, the body of work on the social dimensions of both invasive species and ecological restoration demonstrates the ways in which people construct naturalness in accord with their values and cultural context. By exploring the extent to which people perceive invasive species as reducing naturalness and how ecological restoration is perceived to restore it, these subjects serve as excellent conceptual lenses for exploring constructions of nature. This study explores the subtle variations in environmental values and perception of naturalness among a study population who self-identify as pursuing the same goal: ensuring the continued protection of the Oak Ridges Moraine. The Moraine is a partly urbanized landform in southern Ontario that is situated within a complex hybrid socio-ecological landscape. It is also the subject of an active and high profile conservation movement that has spanned over 40 years. Using a combination of interviews and Q Method, this study explored how citizens engaged in Oak Ridges Moraine conservation perceive both the current and ideal state of naturalness on the Moraine, with specific emphasis on how the discourses these citizens use to frame the Moraine invoke the concept of naturalness Findings from this study reveal that Moraine activists represent a conservation paradox: they value the natural, non-human qualities of the landform, yet at the same time identify the Moraine as a hybrid landscape with both social and ecological qualities. In particular, respondents indicated a strong interest in naturalness in the context of invasive species and ecological restoration, yet at the same time identified the naturalness of the Moraine to be a lesser priority in the face of urban development pressures. In this way, citizens engaged in Moraine conservation respond to the hybrid quality of the Moraine landscape by moving beyond the binary distinction between nature and society, situating themselves as both apart from and a part of the landscape at the same time. This finding demonstrates how values for conserving nature are affected by hybridity between social and ecological systems, and suggests how embracing the paradox of hybrid nature can contribute to understanding and managing complex socio-ecological systems.
190

Impact of inserting a thiol methyltransferase gene on the competition between halide methylation and ethylene production in tobacco.

Abida, Fatma January 2011 (has links)
Plants are exposed to a variety of environmental stresses, ranging from insects and phytopathogens known as biotic stressors, to edaphic stressors including drought and salinity - clustered under the group of abiotic stresses. Facing these pernicious risks, plants have adopted several strategies to survive in stressful environments. With contemporary advances in technology and scientific research, it is possible to insert a specific gene or trait into a plant in order to confer salt tolerance. For example, a thiol methyltransferase enzyme in cabbage converts Cl¯ and other halide ions into their corresponding methyl halides, which are released directly into the air. Cloning the TMT1 gene and functionally expressing this gene into tobacco plants conferred salt tolerance on these plants. Although increased salt tolerance is a favourable and beneficial trait for plant productivity, the emission of methyl halides into the atmosphere can be noxious for the environment. Indeed, methyl halides are some of the factors contributing to climate change, widely believed to be the foremost environmental problem of the twenty-first century. Climate change is affecting all forms of life on earth and its impacts are often severe and irreversible. For that reason, it has been placed at the forefront of the international political agenda. The present study focused on two main physiological traits of stress resistance in tobacco plants which have been genetically engineered with the cabbage TMT1 gene: The production of methyl halides, particularly methyl chloride, as a way to confer salt tolerance; and synthesis of the stress hormone, ethylene. Both pathways share a common metabolite, S-adenosyl-L-methionine (SAM), for the synthesis of the final products. SAM, derived from the amino acid methionine (Met), is a universal methyl group donor. It plays essential roles in plant metabolism, by acting as a precursor for ethylene, polyamines, and vitamin B1 synthesis, and as a source of atmospheric dimethylsulphides. Therefore, it is important that the plant maintains the SAM pool at a level sufficient to serve all the different metabolic pathways. The present work set out to determine whether addition of another SAM-dependent pathway through TMT insertion in tobacco plants would negatively affect ethylene synthesis by lessening the amount of SAM available for ethylene biosynthesis. Detailed experimental studies were conducted, including in vitro and in vivo experiments, to examine the potential effect of TMT gene insertion on SAM availability for ethylene synthesis in tobacco plants. Three series of in vitro tests, differing by the number of leaf discs used, the final headspace volume in each flask, the incubation period in the different solutions and the time of introducing salt solutions, were carried out. Data obtained from two series of in vitro experiments revealed a decrease in ethylene emission when salt solutions were added at the beginning of the experiment and when leaves where incubated overnight in the presence of 0.1 M NaBr, coupled with the production of methyl halides, whereas the other series of in vitro tests as well as the in vivo results showed no alteration in ethylene accumulation because of TMT insertion when tobacco leaves were exposed to salt treatments. According to the results presented in this study, the amounts of available SAM in transformed tobacco are likely sufficient to serve both ethylene and methyl halides biosynthetic pathways. Besides, in vivo results indicate that inserting the TMT1 gene that improves salt stress resistance in tobacco should not dramatically alter ethylene synthesis, and therefore, would be unlikely to affect any physiological trait associated with ethylene production if this gene is used to engineer salt tolerance in high-value crops. Although TMT insertion does not alter ethylene emission in transgenic plants and tends to be an efficient tool to confer salt tolerance in halo-intolerant crops, its environmental cost is of great concern and, therefore, should be taken into consideration to mitigate the amounts of methyl halides emitted into the atmosphere because of this insertion.

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